This invention relates to ink jet printing systems, and in particular, such systems which employ a controller for controlling multiple printheads which are spaced for printing on moving surfaces such as on cartons or boxes being fed forward by a conveyor.
Ink jet printing systems include a plurality of ink jet printheads, each having a matrix of ink jets. Each ink jet has a nozzle constituting a valve seat at its outlet end, the seat having an orifice for injection of drops of ink. A solenoid actuated valve member engages and disengages from the seat to close and open the orifice. A controller for each printhead including a microprocessor, processes data for actuating the solenoids to print messages and to store data. In the past, such controllers communicated with each printhead via a separate cable for each printhead which directly connected the controller to each printhead. In addition, such controllers employed a ASCII data format in which parallel data was provided to each of the printheads. This required a large amount of cabling and required each printhead to print a separate line of text information. There is a need for an ink jet printing system which reduces the amount of cabling between the controller and the printheads and which communicates with the printheads via a serial data format. There is also a need for the ability for such a system to allow one printhead to print more than one line of text or to configure the system such that a text line can span across more than one printhead.